Dell OptiPlex 745 - Manual (Page 190)

System Board Components
Cable Cover (Optional)
Attaching the Cable Cover
1 fan shroud/ heat sink assembly 4 hard drive
2 speaker (optional) 5 security cable slot
3 memory modules (2) 6 chassis intrusion switch
1 fan connector (FAN_FRONT) 8 clear CMOS jumper (RTCRST)
2 internal speaker connector (INT_SPKR) 9 password jumper (PSWD)
3 system board speaker (BEEP) 10 hard-drive power connector (SATA_PWR)
4 channel B memory connector (DIMM_2) 11 fan connector (FAN_REAR)
5 channel A memory connector (DIMM_1) 12 intrusion switch connector (INTRUDER)
6 SATA data cable connector(SATA0) 13 processor (CPU)
7 battery (BATT)